This paper established high resolution model about ocean dynamic in XiangShan harbor and its adjacent sea based on FVCOM,reappeared the seasonal variation characteristics of its ocean dynamic.We also studied the formation mechanism of the tide phase lag between the tidal currents in Fo Du channel and Niu Bi mountain channel and researched the impacts of sea level change and sea reclamation accumulate effect on ocean dynamic in Xiang Shan harbor.It can be found,in the sea between Gang Pan mountain and the entrance of Xiang Shan harbor,there are almost clockwise reversing current on surface and counterclockwise reversing current on bottom in summer,but in winter,the reversing current are all clockwise and its reversing character is more obvious.In the sea out the entrance of Xiang Shan harbor,they are all clockwise rotary currents on surface and bottom;the currents are almost reversing with cross distribution of counterclockwise and clockwise directions in the sea between Gang Pan mountain and Tie harbor,these are both the same on surface and bottom.The seasonal variation characteristics are not obvious in these two sea areas.The dynamic process of Luo Tou channel and Fo Du channel is the reason that make the tide phase lag between the tidal currents in Fo Du channel and Niu Bi mountain channel.If the water exchanges between the two channels is cut off,the tide phase lag between the tidal currents in Fo Du channel and Niu Bi mountain channel will disappear.Impacted by yearly sea reclamations between 2003 to 2012,in Xiang Shan harbor,the mean spring tide range is increased by 11.44cm,the mean high tide is increased by 5.9cm,the mean tidal prism is reduced by 3.72%,the water exchange rate in 30 days is reduced by 2.5%.The sea level rise makes the amplitudes of all tidal constituents bigger,and also intensifies the impacts of sea reclamations accumulate effect on ocean dynamic in Xiang Shan harbor.